If you find the videos are not deleted after resetting/restoring, please note that this is normal. Because reset/restore only sets some or all settings to default but doesn’t delete videos in the SD card.
Applies to: All cameras that have the SD card slot
To delete certain videos from the SD card, please remove the SD card from the camera and delete them on a computer.
To delete all the videos on the SD card, please refer to these articles:
To delete all the videos in the HDD, please refer to this article: How to Format HDD
Here is an article to tell you the difference between a hard reset and a software restore: